Thermic siphon



March 21, 1939'.

E. J. REARDON THERMIC S I PHON Filed June 2, 1958 Patented Mar. 21, 1939UNITED STATES PATENT OFFICE THERBHC SIPHON poration of DelawareApplication June 2, 1938, Serial No. 211,422

14 Claims.

This invention relates to improvements in thermic siphons and itconsists of the matters hereinafter described and more particularlypointed out in the appended claims. The thermic siphon with which thepresent invention is more particularly concerned is anelement employedin a locomotive firebox for increasing the water steaming andcirculating eificiency of the associated boiler. Such an elementgenerally takes the form of an upright, flat hollow body, the open topof which is operatively engaged in the crown sheet, to form the outletof the element. Said element often includes a downwardly and forwardlyextending bottom that terminates in a tubular neck which opens throughone of the other sheets of the firebox to form the inlet or intake forthe element.

In order to obtain as much heating surface as possible, it has becomethe practice to increase the length of the element as much as theconditions in the firebox will permit. It is also the common and desiredpractice to employ a fire arch in connection with such elements, thearch being supported by engagement with the bottom portion of theelement. Again in order to accommodate properly the products ofcombustion as they leave the fuel bed so that they may pass over thearch to the flues, it is necessary that the upper end of the arch bespaced a considerable distance downwardly from the crown sheet. Becauseof the space limitation within the firebox, a design having the abovedesired characteristics results in the bottom portion more nearlyapproaching the horizontal than is the. case where a relatively smallelement is used or where an arch is not desired. In other words, thebottom portion of the element has a relatively smaller inclination orpitch.

Thus in constructions wherein the bottom is of low pitch, it is obviousthat the water cannot as readily rise along said bottom as it could in aconstruction having a greater inclination or pitch. In short,circulation of the water along the bottom wall is not as rapid andvigorous as is the case where the bottom is of steeper pitch.

With the less rapid circulation of Water along the bottom of theelement, certain conditions arise in the element itself which thepresent invention seeks to overcome. For instance, when such elementsare employed in connection with a fire arch, the area of the element onthe underside of the arch directly exposed to the fire in the firebox isrelatively small. Thus the fire is concentrated or confined to a smallarea of the element before it spreads out to pass to the other parts ofthe firebox on its way to the fiues. In

oil burning locomotives, this condition is more noticeable because ofthe concentration of the flame on one spot or surface of the element.Under such conditions, the water in the element on the water side ofsaid spots or areas is often flashed into steam causing the formation ofa steam pocket or vapor lock in the bottom of the element which therelatively slower moving water does not immediately dislodge. Thisprevents flooding said spots or areas with water. Such locks or pocketsbeing devoid of the cooling effect of the circulating water, the metalof the element is in a dry condition. At times the metal of the siphonin the area of said pocket becomes overheated and may even be pressedoutwardly as a bulge or blister. At times cracks or fissures appear andin some instances said elements burn out at these spots or areas.

One of the objects of the invention is to provide simple and efiicientmeans in a thermic siphon for automatically and continually coductingcooler boiler water from beyond the outlet end of the siphon anddirecting and discharging it against those portions of the element alongwhich steam pockets and vapor locks have a tendency I to form.

A further object of the invention is to provide means for use inelements of this kind which has no moving parts and requires noattention so that the life of the associated element and the periodsbetween required servicings are increased.

Another object of the invention is to provide means whereby the watermoving upwardly in the siphon can be divided into streams which assistin preventing conflicting currents and hence facilitate the rapiddischarge of the heated water and steam.

The above mentioned objects of the invention, as well as others,together with the advantages thereof will more fully appear as I proceedwith my specification.

In the drawing:

Fig. 1 is a longitudinal vertical sectional view through the firebox endof a locomotive boiler embodying the preferred form of the invention.

Fig. 2 is a transverse vertical sectional view on an enlarged scale, astaken on the line 22 of Fig. 1.

Fig. 3 is a detail horizontal sectional View through a part of Fig. 2 astaken on the line 3-3 of Fig. 2.

Referring now in detail to that embodiment of the invention illustratedin the accompanying drawing and more especially to Fig. 1 thereof, thefirebox therein shown comprises a flue sheet 5,

rear sheet 6, crown sheet 1 and side sheets 8, the bottom portion of theflue sheet forming the inner throat sheet 9, all arranged in themannerfound in fireboxes of this kind. ill indicates the barrel of the boiler,H the top sheet thereof and I2 and I3 indicate the outer throat sheetand the back sheet thereof respectively. The sheets lll2 l3 coact withtheconventional outer side sheets (not shown herein) in providing theusual side Water legs and the front throat l4 and back water leg l5respectively, all bottomed by a mud ring and which mud ring appears inFig. 1. In the boiler shell are the fines l6 which extend forwardly fromthe flue sheet toward the usual smoke,

box and l 1 indicates the fuel door opening formed by coacting parts ofthe sheets 6 and I3 respectively. The construction above described,which of course is staybolted in the conventional manner, may well betaken as typical of that found in locomotive boilers now in general use.

To increase the water steaming and circulating efiiciency of suchboilers, additional heating elements are employed in the firebox andsuch elements usually draw boiler water from a water leg or other pointand discharge the same through the crown sheet. By way of illustrationand not by way of limitation, I have illustrated a construction in whichthe intake is at the front water leg.

l 8 indicates such a siphon or element as a whole and the number andsize of such elements or siphon employed in a firebox is dependent uponthe width and length of the firebox. Said siphon, as here shown,comprises a flat hollow body E9 of substantially triangular shape and atubular inlet neck 20. The siphon body includes spaced side wall 2l2|,front and rear walls 22 and 23 respectively and a downwardly bulgedbottom portion 24 that merges at one end into the neck and is connectedby a rounded corner or pocket 25 with said rear wall. The corner 25 isspaced downwardly a considerable distance from the crown sheet. Such aconstruction is often desired because it permits the use. of a longerbrick arch 26 without bringing the rear top end of the arch too close tothe crown sheet. In other words, a considerable throat is providedbetween the arch and the crown sheet. A part of the brick forming thisarch rests upon the top portion of the bulged bottom of the siphon.Thus, it is apparent that only a relatively small portion .of thesiphon, as formed by said bottom is exposed to the flames in the fireboxbeneath the arch. It is also clear that the bottom of the siphon is ofless pitch or inclination than if the bottom extended to a point closerto the crown sheet but still in the plane of the wall 23.

The side walls 2 l--2l of the body of the siphon are connected togetherby staybolts 21. The top end of the side and end walls of the siphonareflanged outwardly as at 28 to engage and be secured in a suitableopening provided therefor in the crownsheet. As shown herein, the bottomend of the neck 28 is engaged in and welded to a flexible diaphragm 29formed in the inner throat sheet.

In operation the siphon is subjected to the heat of the burning fuel inthe firebox andthis, of course, raises the temperature of the waterwhereby a portion is converted into steam. Such steam and water in thesiphon are displaced by the heavier and cooler water from the neck 20and lower part of the boiler, to pass upwardly through the siphon bodyinto the boiler water space above the crown sheet. This action resultsin the 'entrance of water from the front throat l4 and through the neck20 at a high velocity. As the water enters the body from its neck, itexpands so that its velocity is reduced with a corresponding reductionin water movement along the bulged bottom as the water and steam bubblesmove upwardly in the body. By reason of the arch, it is apparent thatwith only relatively small areas of the siphon being exposed below thearch, the flames have a concentrated or confined action on said exposedareas. This action almost instantly flashes the water along said areasinto steam, thus at times producing high pressure steam pockets, whichovercome the relatively slow velocity of the Water as it moves along thebottom. Vapor locks at these areas occasionally results. The steam inthe vapor locked pockets cannot readily release itself and move'or climbupwardly toward the top of the siphon because of the cooler and heavierwater above holds it stationary. Thus the interior surfaces of theseareas may remain substantially dry and if this condition exists for aconsiderable period in any one spot, the pressure in the siphon forcesthe metal in said areas outwardly to produce a bulge or pocket that isvisible from the fireside or outer surface of the bulged bottom. Theaction above mentioned is more pronounced and visible in oil burninglocomotives wherein the flames from the burner is concentrated along oneor more spots or areas of the bulged bottom. Such action also seems tobe more prevalent where the bottom inclination is not so steep, i. e.,where the pitch'is not so great.

To overcome this objection without the use of moving parts but by partsthat function automatically and continuously in accordance with thenatural laws governing steam boiler operation, I provide the following:In the body of the siphon I locate one or more longitudinally spacedupright conduits which extend from a point adjacent the bulged bottom toa point above the open top of the siphon but not above the normal levelof the boiler water in the boiler shell. It is desired that each conduitbe surrounded by water and therefore tubes 30 are employed as suchconduits, the tubes having an outside diameter less than the spacingbetween the sheets 2| of the body l9. Said tubes are disposed betweenthe staybolts 21 in adjacent vertical rows and the bottom end ispreferably bent to face in a direction of the flow of water along saidbottom. This arrangement of said end best appears at 3| in Fig. 1. topend of said tube is expanded or belled out- The wardly to increase itsdiameter as appears at 32 in Figs. 1 and 2. e

To support the tubes in place, I employ clips 33 that are secured toopposite sides of top end portions of each tube and these clips have ahooked engagement with the topmost staybolts of the two vertical rowsbetween which the tube is located. The vertical column outside of andadjacent any given tube is composed of steam and water. There may besteam bubbles of considerable size especially near the bottom. Thecolumn within the tube is composed more nearly of water alone. Hence themean density of the, column of water within the tube is greater than thedensity of the adjacent steam water column so that an 'overbalancin-gtakes place resulting in circulation of water downwardly within thetube.

This action is aided by having the bottom or discharge end of each tubefaced away from the direction in which the water normally flows alongthe bottom. In this instance the tubes are bent toward the rear. Thereis a sort of aspiratingv action which includes downward flow in thetubes. The water discharging from the bottom of the tubes impinges uponthe bottom and breaks up vapor lock so that dry areas cannot develop tobulge or blister outwardly. This action is continuous so long as steamis being made in the boiler and as there are no moving parts, there isnothing to wear out. Therefore, the tubes are good for the life of thesiphon without requiring servicing.

By facing the bottom end 3| of the tubes in the direction of the flow ofwater along the bulged bottom of the siphon, there is also lesspossibility of steam entering the bottom ends of the tubes.

The tubes in addition to providing means for conveying water downwardlyalso serve to divide the siphon as a whole into a number of parts thusproviding spaced channels which aid in directing the flow of water andsteam upwardly. There is thus less conflict of water currents which canimpede the free upward flow.

The structure before mentioned is advantageous in that it prevents steampocket and vapor lock conditions along the bottom of the siphon. Thesaid structure is indeed simple in character and may be provided in asiphon at but a very slight additional cost.

While in describing the invention I have referred in detail to the form,arrangement and construction of the parts thereof, the same is to beconsidered only in the illustrative sense, so that I do not wish to belimited thereto except as may be specifically set forth in the appendedclaims.

I claim as my invention:

1. In combination with a locomotive firebox including a crown sheet,side sheets, fiue sheets, throat sheet and back sheet, a water steamingand circulating element in the firebox and having an outlet end openingthrough the crown sheet and having an inlet end opening through one ofthe other sheets of the firebox and having a bottom portion, and meansin said element and extending from a point adjacent said bottom portionto a point adjacent said outlet for conducting boiler water from a pointadjacent said outlet end to a point adjacent said bottom.

2. In combination with a locomotive firebox including a crown sheet,side sheets, flue sheets, throat sheet and back sheet, a water steamingand circulating element in the firebox and having an outlet end openingthrough the crown sheet and having an inlet end opening through one ofthe other sheets of the firebox and having a bottom portion, and atleast one substantially upright tubular member arranged in andapproximately surrounded by the water in said element and extending froma point adjacent said bottom portion to a point adjacent said outlet endfor conducting boiler water from a point adjacent said outlet end tosaid point adjacent said bottom portion.

3. In combination with a locomotive firebox including a crown sheet,side sheets, fiue sheet, throat sheet and back sheet, a water steamingand circulating element in said firebox and including a hollow bodyhaving an outlet end opening through the crown sheet and also includinga downwardly and forwardly inclined bottom that terminates in an inletneck opening through one of the other of said sheets of the firebox, andmeans in said body and extending from a point adjacent said inclinedbottom to a point adjacent the outlet end of said body for conductingboiler water from a point above said outlet end to a point adjacent saidinclined bottom.

4. In combination with a locomotive firebox including a crown sheet,side sheets, fiue sheet, throat sheet and back sheet, a water steamingand circulating element in said firebox and including a hollow bodyhaving an outlet end opening through the crown sheet and also includinga downwardly and forwardly inclined bottom that terminates in an inletneck opening through one of the other of said sheets of the firebox, andat least one tubular member arranged in said body and surrounded by thewater therein and extending from a point adjacent said inclined bottomout through the outlet end of said body for conducting boiler water froma point above said outlet end to said point adjacent said inclinedbottom.

5. In combination with a locomotive firebox including a crown sheet,side sheets, flue sheets, throat sheet and back sheet, a water steamingand circulating element in the firebox and having an outlet end openingthrough the crown sheet .and having an inlet end opening through one ofthe other sheets of the firebox and having an upwardly and rearwardlyinclined portion between said ends, and means in said element andextending from a point adjacent said inclined portion out through saidoutlet end for conducting boiler water from a point beyond said outletend to said point in said inclined portion of said element, said end ofsaid means adjacent said inclined portion being formed to face indirection other than toward the inlet end of said water steaming andcirculating member.

6. In combination with a locomotive firebox including a crown sheet,side sheets, flue sheet, back sheet and throat sheet, a water steamingand circulating element in said firebox and including a fiat elongatedhollow body having an outlet end and opening through the crown sheet andalso including a downwardly and forwardly inclined bottom thatterminates in an inlet neck that opens through one of the other of saidsheets of the firebox, and a plurality of means arranged in and spacedlongitudinally of the body and each extending from points adjacent saidbottom out through the outlet end of said body for conducting boilerwater from points above said outlet to said points adjacent saidinclined bottom.

'7. In combination with a locomotive firebox including a crown sheet,side sheets, flue sheet, back sheet and throat sheet, a water steamingand circulating element in said firebox and including a flat elongatedhollow body having an outlet end and opening through the crown sheet andalso including a downwardly and forwardly inclined bottom thatterminates in an inlet neck that opens through one of the other of saidsheets of the firebox, and a plurality of tubular members arranged inlongitudinally spacedrelation in said body and surrounded by the watertherein and extending from points adjacent said bottom out through saidoutlet end of the body for conducting boiler water from points abovesaid outlet to said points adjacent said bottom.

8. As an article of manufacture, a water steaming and circulatingelement for use in a locomotive firebox and including an inlet end andoutlet end and an inclined bottom portion between said ends, and meansproviding a conduit in said element extending upwardly from a pointadjacent said bottom portion to a point above said outlet end.

9. As an article of manufacture, a thermic siphon embodying therein afiat hollow body portion with a downwardly and forwardly inclined bottomthat terminates in a tubular inlet neck, the top end portion of the bodyforming the outlet for said body, and a plurality of substantiallyupright tubular members spaced longitudinally in the body andterminating at one end adjacent said bottom and terminating at the otherend at points beyond the outlet for the body.

10. As an article of manufacture, a water steaming and circulatingelement for use in a locomotive fireboxand including an inlet end andoutlet end and a bottom portion, means providing a conduit in saidelement extending upwardly from a point adjacent said bottom portion toa point adjacent said outlet end.

11. As an article of manufacture, a water steaming and circulatingelement for use in a locomotive firebox and including an inlet end andoutlet end and a bottom portion, means providing a conduit in saidelement extending upwardly from a point adjacent said bottom portion toa point adjacent said outlet end, the bottom end of said conduit beingfaced away from the inlet end.

12. As an article of manufacture, a water steaming and circulatingelement for use in a 10- comotive firebox and including an inlet end andoutlet end and a bottom portion, and a plurality of substantiallyupright tubular members, spaced longitudinally in the body andterminating at one end adjacent said bottom portion and at the other endadjacent the outlet.

13. As an article of manufacture, a water steaming and circulatingelement for use in a locomotive firebox and including an inlet end andoutlet end and a bottom portion, and a plurality of substantiallyupright tubular members, spaced longitudinally in the body andterminating at one end adjacent said bottom portion and at the other endadjacent the outlet, the bottomends of said tubular members being facedaway from the inlet. 7 r

14. As an article of manufacture, a water steaming and circulatingelement for use in a locomotive firebox and including an inlet end andoutlet end and a bottom portion, and a plurality of substantiallyupright tubular members, spaced longitudinally in the body andterminating at one end adjacent said bottom portion and at the other endadjacent the outlet, the bottom ends of said tubular members being bentaway from the inlet. V

EDWARD J. REARDON.

